Delineating patterns of social affiliation and hierarchical relations in group living rhesus monkeys is very labor intensive. We propose to develop and implement innovative new software and hardware technology that will automate the continuous collection of social interaction data in a complex species-typical rhesus monkey social group. The proposed system will continuously and simultaneously track the precise 3D locations of multiple individuals in a large social group of monkeys in their half acre living area Individual identification will come from comfortable collars, we will design and build, that contai active RFID tags that continuously broadcast each animal's unique code. RFID detectors within and around the compound's periphery allow triangulating each animal's precise location to within 25cm as well as their direction and velocity of movement. We will track the adult males and females that make up the core of the social hierarchy (45 individuals in total). Distance between individuals is a key diagnostic for inferring social affiliation as monkeys are rarely withn 25cm of each other by accident. Thus knowing the amount of time spent at that distance allows inferring affiliative relations. The patterns of affiliation, avoidance, and time in close proximit will allow inferring the social hierarchy of the group. In combination with social network analysis, we will identify patterns of group association and social instability. In addition, we will develop an deploy (in years 3 and 4) a RFID-guided camera system that automatically records high resolution video of predetermined target subjects without human intervention, allowing significantly increased efficiency for later human behavioral coding from these video snippets. Three software systems will be developed under this project: 1) behavioral inference software that infers affiliative, hierarchical, aggressive, and sexual behavior from the automated tracking data; 2) social network analysis software to identify social instabilities; 3) video recognition software that will automate the coding of social behavior from the video snippets collected with the RFID-guided cameras. Together this combined hardware and software will provide an enhanced animal resource making possible easy investigation of the social impact of a variety of manipulations, from drugs to neural insult. In addition, this system can be used to monitor group health and identify individual sickness behavior. This animal resource would facilitate research funded by NIMH, NIDA, or NICHD, and support and enhance primate colony management.